Jackson's debut Hobbit film, An Unexpected Journey, received only lukewarm garlands from reviewers, in contrast to the critical adoration fostered by the New Zealand film-maker's Lord of the Rings trilogy a decade ago. But part two, which features the debut of Smaug, the Benedict Cumberbatch-voiced dragon, is picking up strong early reviews.

Nearly everything … represents an improvement over the first instalment of Peter Jackson's three-part adaptation of JRR Tolkien's beloved creation," "After exhibiting an almost craven fidelity to his source material the first time out, Jackson gets the drama in gear here from the outset with a sense of storytelling that possesses palpable energy and purpose. Toward the end, his perennial tendency to let bloat creep in reasserts itself to an extent … he has a hard time knowing when enough is enough even as the three-hour goalpost looms dead ahead. But for the most part he moves the episodic tale along with reasonable speed for a leviathan while serving up enough fights, close shaves and action-filled melodrama for an old-fashioned movie serial or a modern video game.

One problem with the former film was that it re-trod too closely the footsteps of the Fellowship: it was difficult to share Bilbo's awe at entering Rivendell, given that we'd already been there 11 years before. Here, you can feel Jackson's relief at having entirely new worlds in which to play.

The forest domain of the Silvan Elves has beauty edged with menace … but the real standouts are Lake-town and Erebor, contrasting but equally stunning showcases of production design. The former, a fog-shrouded, Dickensian burg that we're informed 'stinks of fish oil and tar', is a new, pleasingly earthy flavour for Middle-earth. Kingdom-under-the-mountain Erebor, on the other hand, is the kind of mad location that could only exist on a Weta mega-computer, its centrepiece a stash of wealth so vast it would give Scrooge McDuck a quacking fit.

My colleague Peter Bradshaw is also impressed with the manner in which Jackson has "picked up the pace" in part two.

The Desolation of Smaug is a cheerfully entertaining and exhilarating adventure tale, a supercharged Saturday morning picture.

It's mysterious and strange and yet Jackson also effortlessly conjures up that genial quality that distinguishes The Hobbit from the more solemn Rings stories. The absurdity is winning: you're laughing with, not laughing at. For me, it never sagged once in its mighty two hour 40 minutes running time and the high-frame-rate projection for this film somehow looks richer and denser than it did the last time round. Jackson has shown that he is an expert in big-league popular movie-making to rival Lucas and Spielberg.

The tone is 100% Jackson – a kind of thundering gloominess, cut with the occasional glint of Discworld mischief. Jackson and his co-writers, Fran Walsh and Philippa Boyens, have decapitated bodies twitching on the ground, and a captured dwarf leering at a female elf: 'Aren't you going to search me? I could have anything down my trousers.' Maybe this really is what a lot of people want to see from a film version of The Hobbit, but let's at least accept that Tolkien would probably not have been among them.

The new film currently has a rating of 79% on the review aggregator site Rotten Tomatoes, a full 13-point gain on predecessor An Unexpected Journey, if hardly Oscars-bait territory. The Desolation of Smaug arrives in cinemas worldwide on 13 December 2013.